An apparatus and method for fastening a percutaneous medical device to bone is presented, comprising an anchor which comprises an outer threaded segment and an inner cavity comprising an inner threaded segment. A set of comparators is also preferably included in the configurable address generator in order to detect different addressing conditions. In addition, openings in the shredder support walls allow the size of the waste receptacle to be increased, as well as facilitate disposal of other waste through the opening. The second data associates a first user of the application with a privilege in the first set of privileges. The spacer plates are made of a material with a hardness less than that of the locking plates. A logical result of the comparison between the first field and the first rule entry is inverted to generate a first comparison result.